A pressure sensor is a device or device that senses a pressure signal and converts the pressure signal into a usable output electrical signal according to a certain law. Pressure sensors are usually composed of pressure sensitive components and signal processing units. According to different test pressure types, pressure sensors can be divided into gauge pressure sensors, differential pressure sensors and absolute pressure sensors.

Pressure sensor is a commonly used sensor in industrial practice. It is widely used in various industrial self-control environments, involving water conservancy and hydropower, railway transportation, intelligent building, production automation, aerospace, military, petrochemical, oil well, electric power, ship, machine tool. Pipes and many other industries, the following briefly introduces some common sensor principles and their applications. There is also a medical pressure sensor.
Application of pressure sensor in weighing system
Pressure sensing technology is increasingly being used in commercial weighing systems for industrial control technology. In many pressure control processes, it is often necessary to collect pressure signals and convert them into electrical signals that can be automatically controlled. Pressure control devices made with pressure sensors are commonly referred to as electronic weighing systems, and electronic weighing systems are becoming increasingly important as online control tools for material flow in various industrial processes. The electronic weighing system can not only optimize the production in the product manufacturing process, improve the product quality, but also collect and transfer the data about the material flow in the production process to the data processing center for online inventory control and financial settlement.
In the process automation of weighing, the pressure sensor is required not only to sense the gravity signal, but also the performance must be reliable, the dynamic response is better, and the anti-interference performance is better; the signal provided by the pressure sensor can be directly displayed, recorded, and stored by the detection system. Or for feedback adjustment control. The integrated technology integrates the pressure sensor and the measuring circuit, so that the volume of the whole device is greatly reduced. In addition, the development of the shielding technology will also ensure the anti-interference ability of the weighing pressure sensor, so that the degree of automation of the weighing process is controlled. Further improved.
Application of pressure sensor in petrochemical industry
The pressure sensor is one of the most used measuring devices in the automatic control of the petrochemical industry. In large chemical projects, almost all pressure sensor applications are included: differential pressure, absolute pressure, gauge pressure, high pressure, differential pressure, high temperature, low temperature, and remote flange pressure sensors of various materials and special processing. . Almost all of the petrochemical industry's demand for pressure sensors is focused on reliability, stability and high precision. Among them, reliability and many additional requirements, such as range ratio, bus type, etc., depend on the structural design of the transmitter, the level of machining technology and structural materials. The stability and high precision of the pressure transmitter are mainly guaranteed by the stability and measurement accuracy of the pressure sensor.
Corresponding to the measurement accuracy of the pressure transmitter is the measurement accuracy and response speed of the pressure sensor. Corresponding to the stability of the pressure transmitter is the temperature characteristics and static pressure characteristics of the pressure sensor and long-term stability. The demand for pressure sensors in the petrochemical industry is reflected in measurement accuracy, rapid response, temperature characteristics, static pressure characteristics, and long-term stability.
Application of pressure sensor in water treatment
China's environmentally friendly water treatment industry has developed rapidly in recent years and has broad prospects for the future. The use of pressure sensors in water and wastewater treatment processes provides important control and monitoring tools for system protection and quality assurance.
The pressure sensor converts the pressure into an electrical signal output, which in turn can be used to measure the level of the static fluid and can therefore be used to measure the liquid level. The sensitive components of the pressure sensor are mainly composed of a silicon cup sensitive component, a silicone oil, an isolating diaphragm and an air guiding tube. The pressure P of the measured medium is transmitted to one side of the silicon cup element through the isolating diaphragm and the silicone oil, and the atmospheric reference pressure po acts through the air guiding tube. On the other side of the silicon cup component, the silicon cup component is a cup-shaped single crystal silicon wafer that is thinly processed at the bottom. The bottom film of the cup produces elastic deformation with minimal displacement under the pressure P and Po. The single crystal silicon is an ideal elastic body, and its deformation has a strict proportional relationship with the pressure, and the recovery performance is excellent.
The four bridge resistors formed by the semiconductor diffusion process on the silicon diaphragm are arranged in a square shape. When the silicon diaphragm is deformed by pressure, the two resistors on the diagonal are subjected to compressive stress, and the other two resistors are subjected to tensile stress. Due to the piezoresistive effect of the diffused silicon, the resistance values of the two opposing resistors are increased, and the resistance values of the two resistors are reduced. If a voltage is applied to the A-A terminal, there is a voltage signal output proportional to the P-Po differential voltage between the C-Ds.
Application of pressure sensors in the medical industry
With the development of the medical device market, higher demands have been placed on the use of pressure sensors in the medical industry, such as accuracy, reliability, stability, volume, etc., which need to be improved. Pressure sensors have a good application in minimally invasive catheter ablation and body temperature sensor measurements.
Minimally invasive surgery can not only reduce the trauma of the surgical site, but also greatly reduce the pain of the patient, and the recovery process is also very fast. Can meet such requirements, in addition to the doctor's surgical operation experience, but also with a variety of medical monitoring equipment. Many of the medical devices used for this operation are now tiny, like a variety of catheters and ablation devices. Catheters include thermodilution catheters, urethral tubes, esophageal and central venous catheters, and intracranial pressure vessels. In addition to their conductive function, catheters provide important protection in temperature or pressure sensors, patient pathology, and minimally invasive surgery. Temperature and pressure parameters are key parameters for successful operation.
The ability of the sensor to be placed close to the patient is critical for many applications, such as accurate dialysate and venous pressure in dialysis applications. The pressure sensor must be able to accurately monitor the pressure of the dialysate and blood to ensure it is maintained within the set range.
This type of application requires sensors that are small and capable of withstanding liquid media. In many cases, sensors that are not compatible with liquid media require additional mounting components to protect it, increasing the size, cost, and complexity of the product. Liquid medium tolerance is particularly important when monitoring patient breathing because the sensors here must be able to withstand the patient's cough and exhaled moist air.